二氧化硫衍生物对秀丽线虫毒性研究

发布时间：2018-02-22 20:58

  本文关键词： 二氧化硫衍生物 秀丽线虫 毒性效应　出处：《华中师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：二氧化硫(SO_2)是形成雾霾主要大气污染物之一。其毒害作用主要是通过在机体体液中转化成其体内衍生物(亚硫酸盐和亚硫酸氢盐),然后随血液分布全身,从而对机体各种细胞、组织造成伤害。由于SO_2及其衍生物是一种全身性的毒物,人和动物长期暴露于SO_2污染的大气环境下,其健康受到严重的威胁。因此,研究SO_2的供体(SO_2衍生物)对机体毒害作用的机理是目前本领域的研究热点,具有重要的理论和现实意义。为探明SO_2衍生物对模式生物秀丽线虫(Caenorhabditis elegans)的毒性效应及其毒理机制,本文将线虫暴露于不同浓度的SO_2衍生物(3.2 mL、32 mg/L和320 mg/L)24 h,然后从生物学、生物化学和氧化应激三个方面展开研究。在生物学方面,检测了线虫的生殖能力(包括产卵第二天线虫子宫内怀卵量、总产卵量及其子代数目/卵孵化率)、寿命(最长寿命与平均寿命)及生长发育(体长与体宽)指标;在生化方面,检测了线虫肠道内脂褐质的积累及细胞凋亡情况;在氧化应激方面,用试剂盒测定了线虫体内总抗氧化能力(T-AOC)活性和丙二醛(MDA)的含量。最后对数据进行统计分析得到以下结果。1、SO_2衍生物暴露导致线虫虫体缩短变宽、生殖力下降、寿命缩短。(1)暴露于中、高浓度(32 mg/L和320 mg/L)的线虫其体长极显著性缩短(p0.01)、体宽极显著变宽(p0.01),此外线虫外阴出现畸形发育;(2)暴露于5O2衍生物的线虫各个生殖指标均随着SO_2衍生物浓度上升而下降。相对于对照组,暴露组(3.2 mL、32 mg/L和320mg/L)产卵第二天的线虫子宫内怀卵量分别减少了3.74%、8.29%、32.71%(p0.01);总产卵量分别减少了 4.82%、8.94%(p0.05)和 22.97%(p0.01);子代数目分别减少了 9.30%(p0.05)、24.87%(p0.01)和42.32%(p0.01),即卵的孵化率分别极显著下降了 5%、17.89%、25.98%(p0.01);(3)对线虫寿命的影响表现为:暴露组(3.2 mL、32 mg/L和320mg/L)的线虫平均寿命分别缩短了 0.34天、5.34天(p0.01)和7天(p0.01),最大寿命分别缩短了 3天(p0.05)、6.33天(p0.01)和10.67天(p0.01)。2、对线虫肠道内自发荧光密度定量分析得知,暴露于中、高浓度(32mg/L和320mg/L)的线虫肠道内脂褐质含量有极显著的增加(p0.01),荧光密度分别是对照组的1.19倍和1.28倍。此外,SO_2衍生物暴露诱导线虫发生细胞凋亡。3、暴露于不同浓度SO_2衍生物均降低了线虫T-AOC活性,且中、高浓度(32 mg/L和320 mg/L)出现极显著降低(p0.01),分别下降了 33.02%和65.42%。而中、高浓度(32mg/L和320mg/L)极显著增加了 MDA含量(p0.01),分别是对照组的2.1、3.52倍。本文首次进行SO_2衍生物对秀丽线虫毒性效应的研究。结果表明,SO_2衍生物暴露影响线虫的发育,体形呈粗短型(体长缩短、体宽变宽),并出现畸形发育;导致线虫总产卵量减少、孵化率降低,从而使子代数目显著减少;诱导线虫肠道内脂褐质含量增多,标志着毒物加快线虫的衰老速度而导致其寿命缩短;并引起细胞凋亡和氧化应激(T-AOC活性下降、MDA含量增加)。综上所述,SO_2衍生物对线虫具有多重生物毒性,其毒性机制可能与降低线虫体内T-AOC活性、导致自由基大量积累而引起氧化损伤有关。以上研究成果可为进一步探讨SO_2衍生物的毒性机制,寻找有效预防SO_2及其衍生物中毒的方法提供理论依据。
[Abstract]:Sulfur dioxide (SO_2) is one of the main atmospheric pollutants of haze formation. The toxicity is mainly through the body into derivatives in body fluids in (sulfite and bisulfite), and then with the blood distribution of the body, so the body cells, tissue damage due to SO_2 and its derivatives is a kind of systemic poison atmospheric environment, human and animal exposure to SO_2 pollution, the health is threatened seriously. Therefore, the research of donor SO_2 (SO_2 derivatives) on the mechanism of toxic action is the research hot point in this field, it has important theoretical and practical significance. In order to investigate the SO_2 derivatives on the model organism C.elegans (Caenorhabditis elegans) the toxic effects and toxicological mechanisms, the nematodes were exposed to different concentrations of SO_2 derivatives (3.2 mL, 32 mg/L and 320 mg/L) 24 h, and then from the biology, biochemistry Research on three aspects and oxidative stress. In biology, the detection of nematode reproductive capacity (including spawning second worm eggs of antenna in the womb, the total fecundity and egg hatching rate / number), life (the longest life and life expectancy) and growth (body length and width index); in biochemistry, detect the accumulation and apoptosis of intestinal nematode lipofuscin in oxidative stress; total antioxidant capacity in vivo, nematodes were determined by ELISA Kit (T-AOC) activity and malondialdehyde (MDA) content. Finally, the data for statistical analysis results in the following.1, SO_2 derivatives exposure to nematode body shortening variable width, fertility decline, shorten the life. (1) exposed in high concentration (32 mg/L and 320 mg/L) of the nematode body length was significantly shortened (P0.01), body width significantly variable width (P0.01), this nematode vulva appeared abnormal growth; (2) exposure to 5 O2琛嶇敓鐗╃殑绾胯櫕鍚勪釜鐢熸畺鎸囨爣鍧囬殢鐫，

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